You cab just about squeeze a single stick Lipo in most stock tubes , it's tight and it's best to change it at dinner. Mine lasted till the last game but ran out before the end.
It's a marui recoil so the buffer tube has the recoil weight and mechanism in it. I assume Jcheeseright asked because he didn't see the PEQ at first and was wandering if the batteries were inside the RIS.
yeah pretty much, I don't do standard AEGs now, marui and their recoilly goodness have ruined me so I'm looking for a way to make a M4A1 SOPMOD Block 2 without using a PEQ box (I have a working PEQ15 I'd like to put on it) or having batteries in a crane stock. Have spoken to a couple of recoil gurus and they reckon small thin split pack lipos go either side of the barrel inside the RIS2... just.